1. Field of the Invention
This invention relates to radio receiver antenna systems.
2. Description of Related Art
A well-known problem with radio receivers is fading due to multiple path propagation. The problem arises particularly with mobile receivers when the receiver is in motion, especially when the receiver is for operation in the VHF band.
A known method of alleviating this problem is to use a so-called diversity reception technique. In this technique an antenna arrangement comprising two or more antennas having different reception characteristics, i.e. having receiving polar diagrams of different shape and/or orientation, is used, and the receiver is provided with a switching arrangement whereby the antenna producing the strongest signal at any one time is used as the receiver antenna. Instead of two or more antennas, a single antenna which can be caused by the switching arrangement to operate in different modes may be used.